1. Field of the Invention
The present invention relates to a polypropylene resin composition for an automobile bumper, having a high melt flow index (MI) value, i.e., 15 g/min. or more and relates to an automobile bumper having a surface hardness of 55 (Rockwell R) or more and an excellent coating property, i.e., a paint coated thereon is not easily scratched off.
2. Description of the Related Art
Recently, a polypropylene resin composition has been often used for an automobile bumper, because it is rust-free, much lighter than steel and flexible in design. Various polypropylene resin compositions for automobile bumpers are shown in, for example, Japanese Unexamined Patent Publication (Kokai) Nos. 57-55,952, 58-111,846, 59-98,157, 58-17,139, 57-177,038, 57-207,630, 57-195,134, 57-159,841, and 55-22,494.
Although automobile bumpers made of resin compositions proposed in the above-mentioned patent publications are superior in impact strength, the surfaces of the bumpers are so soft that they are easily scratched. In addition, the fluidity of the resin composition is so deficient that there is much difficulty in the application thereof to the injection molding of automobile bumpers, which has been growing in size in recent years.